【作者】 陈星；

【导师】 朱志杰； 曾祥君；

【作者基本信息】 湖南大学 ， 测试计量技术及仪器， 2006， 硕士

【摘要】 随着配电网的不断发展,电缆的大量敷设,配电网对地电容电流不断增加,我国现有配电网一般采取中性点经消弧线圈接地方式。使用中性点经消弧线圈接地后,可以有效地抑制单相故障时的故障电流,提高了系统稳定性和人身安全。但是,中性点经消弧线圈接地后存在两方面的问题:首先,消弧线圈调谐不当易产生谐振过电压;其次,在中性点经消弧线圈接地系统中,发生单相接地时故障选线困难。本课题就这两方面的问题进行了深入研究,设计了一种消弧线圈自动补偿装置,该装置可测量系统对地电容电流和阻尼率,具有响应快、准确性高的优点;同时提出了一种基于FTU的配电网接地选线方法。本文首先综合比较了各种中性点接地方式的特点,介绍了消弧线圈的基本构成以及调谐原理。分析了消弧线圈接地系统中各种相关参数的计算和推导方法,同时研究了了基于信号注入法的脱谐度和阻尼率测量方法,并在实验中验证了这种方法的有效性。然后论文分析了一种基于FTU接地选线装置的工作原理,提出了一种基于信号融合的接地选线方法,给出了动模实验结果。本课题所开发的装置采用INTEL的16位单片机80C196KC为核心,外围功能电路有CPLD功能模块,具有译码和计数功能;液晶触摸屏模块,具有显示和按键功能;通信接口模块,具有通信功能;A/D装换模块和滤波模块等。软件使用汇编语言开发完成,使用模块化设计,主要分为主程序、显示程序、按键程序、中断响应程序几个部分。最后在抗干扰方面,本装置在硬件和软件方面都使用了多种抗干扰设计方法手段,提高了装置的稳定性。本课题将理论运用和实践相结合,为中性点经消弧线圈接地系统的自动调谐提供了一种新的技术手段,具有广阔的应用前景。更多还原

【Abstract】 With the development of distribution network and the great use of cable, the network’s capacitor current increased fast. Association with the situation of China, the solution is grounding the neuter point by Peterson coil which will decrease the fault current and improve the human security. But it also brings two problems: first, the improper compensation will cause over voltage; second, it’s hard to fault select. In this paper, the research was made to solute these problems. The Peterson coil compensation system has been designed which can measure capacitor current and damp degree; a fault selection method of distribution network which was put forward that based on FTU.At first, this paper summarized the developing and the present state of Peterson coil automatic compensation system, and introduces the basic theory of it. As an important part, the principle of measuring capacitor current and dumping degree has been analyzed. Then, an novel method to measure the capacitor current and dumping degree which is based on the signal inject is put forward. Then, the circuits of this instrument’s hardware are illustrated in this paper, such as CPLD interface, extended memory circuit, real-time clock, and touch screen interface, etc. On the software, the realization of the main program and the subprograms such as display, touch keys and interrupt, are introduced with some flow charts. Finally, system’s measurement error and error compensation method are analyzed, and some measures of anti-interference are taken to improve system’s reliability.The project was finished by combination the theory and the practice, and a new way on Peterson coil automatic compensation is available.更多还原